• Aucun résultat trouvé

Laboratory-scale investigation of the removal of hydrogen sulfide from biogas and air using industrial waste-based sorbents

N/A
N/A
Protected

Academic year: 2021

Partager "Laboratory-scale investigation of the removal of hydrogen sulfide from biogas and air using industrial waste-based sorbents"

Copied!
13
0
0

Texte intégral

(1)

HAL Id: hal-01619255

https://hal.archives-ouvertes.fr/hal-01619255

Submitted on 20 Oct 2018

HAL is a multi-disciplinary open access

archive for the deposit and dissemination of

sci-entific research documents, whether they are

pub-lished or not. The documents may come from

teaching and research institutions in France or

abroad, or from public or private research centers.

L’archive ouverte pluridisciplinaire HAL, est

destinée au dépôt et à la diffusion de documents

scientifiques de niveau recherche, publiés ou non,

émanant des établissements d’enseignement et de

recherche français ou étrangers, des laboratoires

publics ou privés.

Laboratory-scale investigation of the removal of

hydrogen sulfide from biogas and air using industrial

waste-based sorbents

Olumide Wesley Awe, Doan Pham Minh, Nathalie Lyczko, Ange Nzihou,

Yaqian Zhao

To cite this version:

Olumide Wesley Awe, Doan Pham Minh, Nathalie Lyczko, Ange Nzihou, Yaqian Zhao.

Laboratory-scale investigation of the removal of hydrogen sulfide from biogas and air using industrial

waste-based sorbents. Journal of Environmental Chemical Engineering, Elsevier, 2017, 5 (2), p.1809-1820.

�10.1016/j.jece.2017.03.023�. �hal-01619255�

(2)

Laboratory-scale

investigation

of

the

removal

of

hydrogen

sulfide

from

biogas

and

air

using

industrial

waste-based

sorbents

Olumide

Wesley

Awe

a,b,

*

,

Doan

Pham

Minh

b,

**

,

Nathalie

Lyczko

b

,

Ange

Nzihou

b

,

Yaqian

Zhao

a

aDoogeCentreforWaterResourcesResearch,SchoolofCivilEngineering,UniversityCollegeDublin,Newstead,Belfield,Dublin4,Ireland bUniversite’deToulouse,MinesAlbi,CNRSUMR5302,CentreRAPSODEE,CampusJarlard,Albi,F-81013cedex09,France

Keywords: Biogas Activatedcarbon Calciumcarbonatewaste Purification

Adsorption H2Sremoval

ABSTRACT

Biogasisavaluablerenewableenergythatcanbeusedasafuelorasrawmaterialfortheproductionof hydrogen,synthesisgasandchemicals.ApartfromitsmainconstituentofCH4andCO2,italsocontained

variousundesirablecontaminants.TheremovalofthesecontaminantssuchasH2Swillsignificantly

improvethequalityofthebiogasforfurtheruse.Thisworkinvolvedthevalorizationofcalciumcarbonate (CaCO3)-basedsolidwastesfortheremovalofH2Sfromthebiogasstream. Thesolidwastes were

analyzedbydifferentphysicochemicalmethodsCaCO3wasfoundasthemaincomponentofbothsolid

wastes,whiletraceamountsofotherelementssuchasMg,Al,etc.werealsopresent.Thesolidwastes weredispersedinwaterandtheresultedsuspensionsweretestedfortheremovalofH2Sfromthegas

phase,usingatriphasicgas/liquid/solidglassreactoratroomtemperatureandpressure.Acommercial activatedcarbon(AC)andapurecommercialcalcitewerealsousedforcomparisonpurpose.Inaddition, mixturesofACwithCaCO3wasteindifferentratioswerealsotested.Theinfluenceofthematrixofgas

(airorbiogas)ontheremovalofH2Swasevaluated.Bothsolidwastesshowedhigherperformance

comparedtothepurecommercialcalciteforH2Sremoval.ThecouplingofaCaCO3wasteandACallowed

improvingthesorptionperformancecomparedtopurecommercialCaCO3andACusedalone.Theresults

obtainedopenanewpromisingwayforthevalorizationofCaCO3-basedwastesforH2Sremovalfrom

biogas.

1.Introduction

Biogasisarenewableenergyresourcethatcanbeanalternative

solutionfortheworldinsatiableenergydemandsandatthesame

time help in reducing waste and the greenhouse gas (GHG)

emissions[1].It isalsoregardedas carbonneutral becausethe

carbon in biogas comes from organic matter (feedstocks) that

captures this carbon from atmospheric CO2 over relative short

timescale[2]. Whenbiogas is produced, wasteis converted to

energythereby reducingtherefuse mountain(landfill)disposal

andprovidingwithenergysuppliessecuritywithoutany

signifi-cant environment impact [1]. The production of biogas also

provides an eco-friendly, high-value useable by-product

(bio-fertilizer) forsoil conditioningand improvement[2].Thus it is

highlyregardedaseffectivemethodofwastemanagement[3,4].

The chemical composition of biogas largelydepends on the

origins andthekindofsubstrates usedsuchas methanationof

biomass,organicwastesfromsewagesludge,animalfarmmanure,

energycrops,andagro-foodindustrywaste[5].Differentprocesses currentlyexistandcanbeusedforthegenerationofbiogassuchas

anaerobicdigestion,anaerobicco-digestion,landfills,commercial

composting,andagro-foodindustrydigestionfacilities,underboth

mesophilic(35!C)andthermophilic(55!C)conditions[6].

Thecompositionofrawbiogasfromtheanaerobicdegradation

ofsewagesludge,livestockmanure,industrialandagro-bio-waste

areshowninTable1.Thelowerheatingvalueofbiogasrangesfrom

15to30MJ/Nm3andislowerthanthatofnaturalgas,whichis

around36MJ/Nm3[5,6].

Hydrogen sulfide along with other S bearing compounds

(mercaptansetc.)arethemostcommoncontaminantsinbiogas

and their content, which can vary from 100 to 10,000ppm,

dependslargelyonthecompositionoftheorganicmatter,mostly

protein-rich streams. They are also formed in different

* Correspondingauthorat:DoogeCentreforWaterResourcesResearch,Schoolof CivilEngineering,UniversityCollegeDublin,Newstead,Belfield,Dublin4,Ireland.

** Correspondingauthor.

E-mailaddresses:wesley.awe@ucdconnect.ie(O.W.Awe),

(3)

anthropogenic processessuch as; coal combustion,papermills,

food industries, wastewater treatment plants, animal farms,

gasification of biomassor coal for syngasproduction or

petro-chemical processing, etc. [7–9]. So it can be used in chemical

processes for the production of various products, including

syntheticgas(syngas,mixtureofCOandH2),hydrogen,methanol

and otherhydrocarbons[10].Theymustberemovedbefore any

utilizationbecausetheyarehighlycorrosivetothemetallicpartsof

engines,pipes,pumps,compressors,gasstoragetanks,valvesand

reducethelifespanofprocessequipment,mostespeciallyinthe

presenceofwaterandtraceofoxygeninthebiogas.Thisresultin

extracostsofinfrastructuresandmaintenance[11,12].Theyhave

also serious environmental concerns due to their oxidation to

sulfur dioxide (SO2)and sulfuric acid(H2SO4)[2].The

environ-mentalconcernsofH2Sincludeacidrainduetohighsolubilityof

sulfur-containingcompoundsinwater.ThishappenswhenH2Sis

releasedinformofgas,itremainsintheatmosphereandspreadfor anaverageof18h,duringwhichtimeitisoxidizedtosulfurdioxide (SO2)andsulfuricacid(H2SO4).Also,becauseitisacolourlessand

flammablegasthatsmellslikerotteneggs,itcanbeperceivedat

lowconcentrationrangingfrom0.0005–0.3partpermillion(ppm).

However,athighconcentration,apersonmightlosethesenseof

smell,whichposesseriousdangertopeople’shealth,becauseof

false assumptionsthatitisnolongerpresent.Thiscanincrease

theirexposuretohigherconcentrationlevelthatmaycauseserious

health effects. Atconcentration 100–1000ppm, there is loss of

smell, serious respiration troubles, ocular irritation, loss of

consciousness,withimmediatedeathabove1000ppm[2,13].

Basically, therearetwomainutilizationsofbiogas.Itcanbe

eitherupgradedtoreachtheenergeticdensityofnaturalgasor

purifiedforchemicaltransformationprocesses.Biogasupgrading

consistsoftheadjustmentofCO2content,toincreasethecalorific

valueofthebiogastooptimallevel.Thus,biomethaneisthefinal

productwhichcomposesofCH4(95–99%)andCO2(1–5%),with

little or no trace of H2S and other compounds [14]. Biogas

purification involves the removal of harmful, toxic, and/or

unnecessary compounds such as H2S, N2, O2, Si, H, VOCs, CO,

andNH3.PurifiedbiogascontainsmostlyCH4andCO2withlow

contentofcontaminants.

Inrecentyears,severaltechnologieshavebeendevelopedfor

syngas cleaning, and their main differences are related to the

natureoftheoperation.Catalyticprocessesinvolvetheoxidation

ofH2Soversolidcatalysts,inordertoconvertittomolecularsulfur,

sulfide,thiosulfateandsulfate[9,15].Biologicalprocessesutilize bacteriasuchasThiobacillusandSulfolobusfamily,fortheoxidation ofH2Sintoelementalsulfurorsulfate[16].Thisprocessrequires

strict operational conditions to control pressure, temperature,

inputcomposition bacterialand energysources,etc.[17].Other

advancedmethodshadbeeninvestigatedanddevelopedsuchas

hydrateformationforH2Sseparation[18–22].Thesetechnologies

arefound tobeefficientfor biogas purificationand upgrading.

However,theystill needto beimproved for enhancing

perfor-manceandreducingoperationalcost[23].Inthiscontext,thereis

increasinginteresttodevelopnewlowcostandefficientmaterials

assorbentfor biogastreatment. Thishasledtoinvestigationof

industrial and agricultural wastes and sewage sludge [24] as

alternativesorbentsforH2Sremovalfrombiogas.

BiologicaldesulphurizationandbiofiltrationofH2Stechnology

mentionedaboveemployedspecializedmicroorganismstoreduce

thelevelofH2Sinbiogasbyconvertingittoelementalsulfurand

some sulphates, similar to the technique of addition of air or

oxygenintothedigestiontank.Thetechniqueisonthebasisof

lithautotrophicbacteriatouseH2SaselectrondonorandCO2as

carbon source, and also for the development of end-of-pipe

solutionsforbiogasupgrading[25,26].About4–6%ofair/oxygen

wasusedaselectronacceptorandprovidedtheenergyneededfor

lithotrophicgrowthinordertooxidizeH2S[25].Hydrateformation

process was firstly proposed by Yoon and Lee [27] who

Table1

Compositionandparametersofgasesfromdifferentorigins,impuritiesandtheirconsequences[5,12,20,43–47]. Parameters Unit Landfill

Gas Biogasfrom AD Dutch NaturalGas NorthSea NaturalGas

Impactonbiogasutilization MJ/ Nm3 16 23 31.6 40 Lowerheating value KWh/ Nm3 4.4 6.5 8.8 11 MJ/kg 12.3 20 38 47 Density Kg/ Nm3 1.3 1.1 0.8 0.84 Relative density – 1.1 0.9 0.6 0.63 Wobbeindex, upper MJ/ Nm3 18 27 43.7 55 Methane number – >130 >135 – 73 Methane(CH4) Vol-% 35–65 60–70 80–90 85–92 Heavy hydrocarbons Vol-% 0 0 9 9 Watervapour (H2O)

Vol% 1–5 1–5 – – Corrosionincompressors,gasstoragetanksandenginesduetoreactionwithH2S, NH3,CO2toformacids

Hydrogen Vol-% 0 0 – 0

Carbondioxide Vol-% 15–40 30–40 0.2–1.5 0.2–1.5 Decreasingcalorificvalue,anti-knockpropertiesofenginesandcorrosion Nitrogen,range Vol-% 15 0–0.5 14 0.3–1.0 Decreasingcalorificvalue,anti-knockpropertiesofenginesandcorrosion Oxygen Vol-% 1 0 – – Corrosion,foolingincavernstorage,riskofexplosion

Hydrogen sulfide

Ppm 0–100 0–4000 – 1.1–5.9 Corrosion,catalyticconverterpoison,emissionandhealthhazards.SO2,SO3are form

Ammonia (NH3)

Ppm 5 100 – 0 Emission,anti-knockpropertiesofenginesandcorrosionwhendissolved Totalchlorine

asCl"

Mg/

(4)

investigated clathrate phase equilibrium for the

water-phenol-carbondioxidesystembasedontheequilibriumpartitionofthe

componentsbetweengaseousphaseandthehydratephase.Kang

etel.[18]usedthisprincipletoworkongashydrateprocessforthe recoveryofCO2fromfluegas.AccordingtoTajimaetal.[21],the

basicmechanismoftheseparationprocessisaselectivepartition

of the target component between the hydrate phase and the

gaseousphase.Generally,thehydratephaseisstableunderhigh

pressure-low temperature conditions. This has attracted other

researcherstolookatthepossibilityofemployingthistechnology

to reduce CO2, H2S, and other contaminants from biogas and

syngasstreams.

This paper investigated the reactivity of calcium carbonate

(CaCO3)-basedsolid wastes(CCWs)fortheremovalofH2Sfrom

simulatedbiogasmatrix(H2Sinbiogas)andsyntheticwastegas

matrix(H2Sinair),usingtriphasicgas/liquid/solidprocessatroom

temperatureandatmosphericpressure.Themainobjectiveofthe

studywasthedevelopmentofnewandlowcostsorbentsforthe

treatment of H2S in the gas phase. The solid wastes, called

thereafterCCW-D(CalciumCarbonate–basedsolidWaste,sample

D) andCCW-S(CalciumCarbonate–basedsolidWaste,sampleS),

weretakenfromtwodifferentindustrialsitesoftheproductionof

sodiumcarbonateandsodiumbicarbonate,andwereanalyzedby

differentphysicochemicalmethods.Up-to-date,thesewastesare

notvalorizedforanyusefulmaterial.Inaddition,theycontaintrace

amountsofvariousmetalssuchasMg,Al,Fe,Si,Cl,Nawhichare

favourableforthefixationofacidgassuchashydrogensulfide[28–

30].Thesewastesarerich inCaCO3 andcanbereactiveforthe

fixationofacidgasfromthegasphase.Apurecommercialcalcite

(Calcite)andactivatedcarbon(AC)werealsousedasreferences.

TheperformanceofasinglesolidwasteorACwasalsocompared

with theirmixtures containing different weight ratios of solid

wastetoAC.

2. Materialsandmethods

2.1.Materials

TheinitialmaterialsusedinthisstudywereCCW-SandCCW-D

wastestakenfromtwodifferentindustrialsitesandwerebothin

powderedform.Theyweresievedtoeliminateparticleslargerthan

315

mm

anddriedat105!Cbeforeeachsorptiontest.

Purecalcitepowder(CaCO3,>98wt%)fromFisherScientificand

ACpowderfromCARBIO12SA(C1220IG91,>1100m2/g,France)

werealsousedforH2Sremovaltest.TheACwasgrindedandsieved

torecoverparticlessmallerthan315

mm

forsorptiontest.These

twosorbentsarethereafterdesignated“Calcite”and“AC”forpure

calciteandactivatedcarbon,respectively.

2.2.Methods

Differentchemicalandphysicochemicaltechniqueswereused

forthecharacterizationsandanalysis ofthesorbentsbeforethe

H2Sremovaltest. Thermogravimetry-Differentialscanning

calo-rimetrycoupling(TG-DSC)wasperformedinaSDTQ600analyzer

(TA Instruments)witha heatingrate of5!C/minunderairflux

(100mL/min). X-ray diffraction (XRD) data of the solids were

collectedusingaPhillipsPanalyticalX’pertProMPDdiffractometer

withaCuKa(1.543Å)radiationsource.Thisdeviceworkswitha

currentof45kVandanintensityof40mA.Diffractionpeakshave

beenrecordedinthe2urangeof10to70!at0.042!persecond.

Specific surface area was determined by BET method, using a

MICROMETRICSTriStarII3020.Thetruedensityofthesorbents

was carried out by a helium pycnometer (ACCUPYC 1330,

Micrometrics).Particlesizedistributionwascarried outusinga

Mastersizer3000laserdiffractionparticlesizeanalyzer(Malvern

Instrument). Inductively coupled plasma coupled with atomic

emission spectrometryanalysis (ICP-AES) was performedusing

HORIBAJobinYvonUltima2,fortheelementalanalysis.Theionic

chromatography was performed with a Dionex ICS- 3000,

equippedwithaconductivitydetector.

2.3.Experimentalsetup

Thelaboratory-scalesetupwasdesignedandassembledforthe

adsorption test. It consists mainly of three parts: gas feeding,

adsorptionunit(glassreactor,200mL)andH2Sanalyzerasshown

inFig.1.Experimentswereconductedintwophases,firstlywith

syntheticwastegas(basedondriedaircontaining200ppmvH2S),

and secondly with synthetic biogas from Linde France S.A,

containingCH4 (64%), CO2 (31%),H2S(200ppmv)and balanced

withN2(around5%).Allexperimentswerecarried outatroom

temperature andatmospheric pressure.Foragivenexperiment,

100mLofdemineralizedwaterwas introducedintothereactor.

Thenthesyntheticwastegasorbiogascontaining200ppmvofH2S

was passedthroughthereactorattheflow rate of100mL/min

usingamassflowcontroller(SLA5851,Brooks1Instrument).The

reactorwaskeptunderstirringalongtheexperiment(600rpm).

(5)

FortheremovalofH2Sfromairmatrix,anelectrochemicaldetector

(GasAlertQuatro,fromBWTechnologies)wasusedtomonitorand

recordH2Sconcentrationatthereactoroutletevery5s,withthe

detectionlimitof0.1ppmv.FortheremovalofH2Sfromthebiogas

matrix,a

m-GC

(MyGC,Agilent)wasusedtoanalyzethegassample

takenfromtheoutletofthereactor.Infact,thesyntheticbiogas

contained any trace of oxygen sotheelectrochemical detector,

whichneedsO2forthemeasurement,couldnotbeusedforthisgas

matrix. WhenthewaterwascompletelysaturatedwithH2S(by

comparing the inlet and outlet concentration of H2S), 500 or

2500mgofsorbentwassetintothereactortostartthesorption

test.Theexperimentaltestswerevalidatedbyperformingatleast

twosets.Sodiumhydroxide(NaOH)wasusedtostrippedH2Sand

othercontaminantsfromtheexitgaseffluentfromthereactor,

beforedischargingitthroughtheceilingextractorfanfixeddirectly

abovethereactorroom.

In order to comparedifferent experimental conditions with

differentsorbents,thetotalaccumulatedquantityofH2Sinjected

tothereactoratagivenreactiontime(H2Sinput,mg)andthetotal

accumulated quantity of H2S fixed on the sorbent at a given

reactiontime(Accumulatedsorbent,mg)weredefinedand

calculat-edfromtheEqs.(1)and(2),respectively[28]

H2Sinput¼ PQM 106RTCintt ð1Þ Accumulatedsorbent¼ PQM 106RT½Cintt" Z t 0 Coutdt' ð2Þ

Where,Qistheinletflowrate(100mL/min),Misthemolecular

weightofH2S(34.06g/mol),CinistheinletconcentrationofH2S

(200ppmv),CoutistheoutletconcentrationofH2S(ppmv),tisthe

reactiontime(min),Pisthepressureofgas(1atm).

3. Resultsanddiscussion

3.1.Characterizationoftherawmaterials 3.1.1.ICP-AES

The elemental analysis of CCW-S and CCW-Dusing ICP-AES

technique is shown in Table 2. The commercial AC was not

analyzedsinceitcontainsmainlycarbon.ItisseenfromTable2

that the commercial calcite was practically pure, as expected.

CaCO3wasfoundtobethemaincomponentofCCW-SandCCW-D,

but other elements were also present which include different

metals, sulfur,and chlorine. CCW-Dcontained more impurities

thanCCW-SexceptforFe.Thecontentoforganiccompoundswas

negligibleforbothsolidwastes.

3.1.2.XRD

Fig. 2 shows XRD patterns of the initial sorbents. For the

commercialAC, twoweak andbroad peaksaround25 and45!

were observedwhich are characterized for amorphous

carbon-basedmaterial[29–31].For thecommercialcalcite,onlycalcite

wasdetectedasthecrystallinephase.CCW-ShadthesimilarXRD

patternthanthatofthepurecommercialcalcite,whichresulted

fromalonganddeepnaturalcarbonation.Well-crystallinecalcite

of rhombohedral structure was found to be the only major

crystalline phase in this waste. On the other hand, CCW-D

contained both calcite (rhombohedral structure) and aragonite

(orthorhombicstructure).Thepresenceofaragoniteisexplained

byafast-artificialcarbonationofCCW-D.Thecorrespondingmain

peaksareindicatedinFig.2. 3.1.3.Thermogravimetricanalysis(TG)

Thismeasuresweightchangesin amaterialasa functionof

temperatureand/ortimeunderacontrolledatmosphere.Fig.3(a)

presentstheweightlossofthesamplesduringaheatingtreatment

fromambienttemperatureto1000!Cwithaconstantheatingrate.

ForCaCO3-basedsorbents,aweightlossbetween610and800!C

wasobserved.Thiscorrespondstothedecarbonationofthecalcite

(Eq.(3)), which was highly endothermic(Fig. 3 (b)).From this

weightloss,thecontentofcalciumcarbonatecouldbedetermined

asshowninTable2above.Between200and610!C,asmalland

continuousweightlosswasalsoobservedforalltheCaCO3-based

sorbents. This may be due to the decomposition of other

carbonates at low contents (carbonatesof sodium,magnesium

etc.).

CaCO3!CaOþCO2 ð3Þ

For the commercial AC, a slight weight loss (13.4%) was

observed around 100!C which corresponds to the surface

Table2

Mainchemicalcompositionofresidues(CCW-S,CCW-D)andreferenceCalcite.

Materials Concentration(g/kg) Total(g/kg)

Ca CO32"b S Mg Na Fe Othersa

Calcite 434.5)1.2 576)0.4 – – – – – 1010.5)1.6 CCW-S 384.2)2.7 558)1.1 1.1)1.0 1.3)0.7 3.6)1.0 3.9)0.4 0.47 952.1)6.9 CCW-D 357.4)2.5 508)3.4 7.2)2.6 2.4)1.2 9.9)3.2 1.6)0.6 0.40 886.5)13.5 aP,Cu,Mn,Zn,Sn,Al,Cl,Si.

b DeterminedbythermogravimetricAnalysis.

Fig.2.XRDpatternsofthesorbentsshowingaragoniteandcalcite;C:calcite;A: aragonite.

(6)

humidityofAC(Fig.3(c)).Thehighquantityofhumidityofthis materialisexplainedbyitshighspecificsurfacearea(1100m2/g).A

weight loss was then observed above 380!C, due to the

combustion of AC. This combustion was strongly exothermic

which disturbed the furnace temperature, despite the small

amountofsampleusedforthis analysis(16.6mgonly).Asmall

weightlosswasalsorecordedabove650!Cwhichwasduetothe

gasification of coke deposition. Low ash content (<3%) was

observedforthisACindicatingitshighpurity.

3.1.4.Particlesizedistribution

Fig. 4 shows the particle size distribution of all the raw

materials before pretreatment. The commercial calcite had a

bimodaldistributionwithtwopeaksaround0.8and10

mm.

The

particlesizedistributionofthissampleextendedfrom0.1toabout

45

mm.

TheCCW-Sand CCW-Dshowamultimodal distribution

thatextended from0.1 to590

mm,

but themain peakwas also

found around 10

mm.

Finally, the commercial AC presented a

multimodal distribution with a broad peak. The main peak is

located around 210

mm.

Table 3 shows the values of the

characteristicdiameters(d50andd90)ofthepowders.Theaverage

diameter(d50)isthesameorderofmagnitudeforthethreecalcium

carbonates,whichwassmallerthanthatofAC.

Partoftheobjectiveof thisresearchistovalorizetheentire

volumeofresidue.Toensurepropersuspensionofthesolidinthe

lab-scalereactorusedinthiswork(200mL)andthustoavoidthe

depositionofsolidsatthebottomofthereactor,thesolidswere

sifted.Atlaboratoryscale,thefractionofsolidusedwaslessthan

(7)

315

mm

aspreviouslymentioned.Thisfractioncorrespondsto99%

byvolumeofthetworesidues.

3.1.5.Truedensity&specificsurfacearea

Thespecificsurfaceareaandthetruedensityofthesorbentsare

showninTable4.Alltheinitialcalciumcarbonate-basedsorbents

(Calcite,CCW-D,andCCW-S)hadaspecificsurfacearealowerthan

4g/m2,whilethatofACreached1098g/m2.Thetruedensityofthe

calciumcarbonate-basedsorbentswassimilartoeachother,while

that ofAC was smaller.Thisisexplained bythelowdensity of

carbon matrix of AC compared to calcium carbonate of other

sorbents.

3.2.SorptionreactivityintheremovalofH2Sinairmatrix

As stated earlier, H2S can be physically adsorbed, and

chemicallyabsorbedduetothepresenceofsomemetals,which

canactascatalystsorreagents,andalsothesurfacealkalinityof sorbent.Fig.5(a,b)presenttheresultsobtainedfortheremovalof

H2S(200ppmv)indryairmatrix.

InFig.5(a),whichpresentstheoutletconcentrationofH2Sasa

functionofthereactiontime,thepurecommercialcalcitehadthe

lowestreactivityforH2Sremoval.TheoutletconcentrationofH2S

wasmeasuredbythe

m-GC

forthisexperimentwhichexplained

thelimitednumberofanalyzedpoints,butitcanbeseenthatthe

suspensionofpurecalcitequicklylostitsreactivityabovethefirst

two hours of reaction. Among the two solid wastes, CCW-S

presentedlowerreactivitythanCCS-D.Bothsolidwastesquickly

decreasedtheconcentrationofH2Stoabout8ppmvattheoutletof

the reactor for the first min of reaction. Then the outlet

concentrationofH2Sprogressivelyincreasedandstagnatedaround

45–50ppmvfor CCW-Dand 150ppmv for CCW-S. Taking into

accountthelowspecificsurfaceareaofcalciumcarbonate-based

sorbents,itisexpectedthatthephysicaladsorptionofH2Sonthe

surfaceofthesesorbentsisnotenoughforexplainingthestagnant

period,observedforbothsolidwastes.Previousworkofourteam

explained this phenomenon by the catalytic oxidation of H2S,

catalyzedbyvariousmetalspresentinthesesolidwastes(Ca,Mg,

Feetc.)[32].Theacid-basicreactionofH2Swithsolublecarbonate

species (mainly CO32") in the aqueous solution plays also

importantrolefortheperformanceofthesesolidwastes.Inthe

caseof CCW-S,theoutletconcentrationof H2Sdecreasedagain

above 370min. It is supposed that a secondary dissolution of

CaCO3-based particles ofthis sorbent tookplace leading tothe

supplementaryavailabilityofactivespeciesfortheremovalofH2S.

The higher reactivity of CCW-D compared to CCW-S could be

explainedbythepresenceofaragonite(whichwasnotpresented

inCCW-S),aswellasthehighamountofimpurities ofCCW-D.

Aragoniteismoresolubleinwaterthancalcitewhichleadstohigh

availabilityofcarbonateanions fortheneutralizationof sulfide

species, whiletheimpurities (mostly metals andmetal oxides)

catalyzetheoxidationofsulfidespecieswithdissolvedoxygenas

oxidant.

For the commercial AC, the outlet concentration of H2S

decreasedtozeroand waskeptatthis valueforupto175min.

Thenitslowlyincreasedandreached25ppmvafter420min.So,AC

was more performant than the solid wastes during the first

minutesofreaction.ButitseemedthatACcontinuouslylostits

reactivity suggesting the physical adsorption of H2S as the

predominantphenomenon.On theotherhand,calcium

carbon-ate-basedwastesallowedkeepingconstantlytheremovalofH2S

thankstothecatalyticoxidationasthepredominantstep.

Fig.5(b)represents theresultsobtainedin Fig.5 (a)by the

accumulatedquantityofH2Sfedintothereactororfixedbythe

sorbents. This also allows comparing the performance of the

sorbents,and specificallythecalculationofthequantity ofH2S

Fig.4.ParticlesizedistributionsbyvolumeofCalcite,CCW-D,CCW-S,andActivatedcarbon(AC).

Table3

Valuesofthediametersd50andd90oftheinitialsorbents.

Materials d50(mm) d90(mm) Calcite 8.9 17 CCW-S 10.2 75.9 CCW-D 11.2 74.3 AC 24.9 108 Table4

Thesurfaceareaandthedensityofthesorbents.

Materials SurfaceArea(g/m2) AverageDensity(g/m3) Calcite 2.60 2.73

CCW-S 3.23 2.76

CCW-D 3.98 2.70

(8)

fixedby thesorbentata givenreaction time.The curveofthe

accumulatedquantityofH2SfixedbyACwassuperposedormostly

closetothecurveoftheaccumulatedquantityofH2Sintroducedto

thereactorduringthereactiontime.So,mostH2Sintroducedtothe

reactorwasfixedbythissorbent.Bythesameanalysis,CCW-Dwas

more performant than CCW-S and pure calcite. Basing onthe

resultsin Fig.5(a,b),only thecommercialAC and CCW-Dwere

selectedforthestudyofH2Sremovalinbiogasmatrixbelow.

3.3.SorptionreactivityintheremovalofH2Sinbiogasmatrix

ThesyntheticbiogascontainingwasCH4(64%),CO2(31%),H2S

(200ppmv),andbalancedwithN2(around5%),andwasobtained

fromLindeFranceSA.TheremovalofH2Sinthisbiogasmatrixwas

performedwithtwosorbentsACandCCW-D.Fig.6(a)showsthe

outlet concentration of H2S obtained with 0.5 or 2.5g of the

individual sorbents. Note that using the

m-GC

analysis with

manualinjection,therewaslessanalysispointcomparedtothe

electrochemicaldetector.Inallcase,CCW-Dhadlowerreactivity

thanAC.ForbothquantitiesofCCW-Dof0.5and2.5g,theprofileof theoutletconcentrationofH2Swasquitesimilar.Thisisexplained

bythefactthatthesyntheticbiogasdidnotcontainoxygensono

oxidationofsulfidespeciestookplace.DissolvedH2Scouldonlybe

neutralized by carbonate anions (CO32") coming from the

dissolutionofcalciumcarbonateandthisisslowbecausecalcium

carbonate (in both calcite and aragonite forms) haslow water

solubility. The physisorption of H2S must be low in this case,

becauseCCW-Dhad verylowspecificsurfaceareaandwasnot

porous. Thus, the outlet concentration of H2S progressively

increase and was closetotheinlet valueafter540minof test.

Incombinationwiththeresultsintheairmatrix,wecanseethat

the catalytic oxidation is predominant when using calcium

carbonatewastesas sorbents.In fact, theanalysis oftheliquid

phase recovered after test in the air matrix evidenced the

formationofoxidationproducts(sulfate,sulfite,andthiosulfate).

Thiswaspreviouslydetailed[32].Ontheotherhand,

physisorp-tion,whichisfavourablebyhighspecificsurfaceareasuchasthe

caseofAC usedin thiswork(1098m2/g),mustbepredominant

when usingAC as sorbent.Thisis not (orless)affectedby the

presenceorabsenceofoxygeninthegasmatrix.Theincreaseofthe

quantityofACfrom0.5to2.5gthusallowedstronglydecreasing

theoutletconcentrationofH2Sduringthereaction.After540min,

theoutletconcentrationofH2Swas157and27ppmvusing0.5and

2.5gofAC,respectively.Fig.6(b)representstheresultsobtainedin

Fig.6(a)by theaccumulatedquantity ofH2S. The effectof gas

matrixontheperformanceoftheprocesswasagainevidenced.

Fig.5.ExperimentalresultsinH2Spassingoverthesorbents(AC,CALCITE,CCW-DandCCW-S)fortheremovalofH2S(200ppmv)dilutedinairwithexperimentalconditions ofroomtemperatureandpressure,500mgofsorbent,100mL/minofinputgas,100mLofwater:(a):OutletconcentrationofH2S;(b):AccumulatedquantityofH2Sfixedon sorbent.

(9)

When0.5gACwasused,theperformancewashigherwithair

matrix(11mgofH2Saccumulatedonthesorbentafter400minof

reactiontime,Fig.5(b))thanwithbiogasmatrix(versus6mgof

H2Saccumulatedonthesorbentafter400minofreactiontime,

Fig.6(b)).Infact,inFig.5(a),astagnantperiodatzeroppmvfor

175minwasobservedwiththeairmatrixbutitwasnotthecase

withthebiogasmatrix.Takingintoaccountthecompositionofthe

syntheticbiogasusedinthiswork,mostlywiththepresenceofCH4

andCO2,itissupposedthatthesetwomoleculeshadcompetitive

adsorptionagainstH2S.Thus,itdecreasedtheperformanceofACin

thebiogasmatrixforthefixationofH2S.Thecompositionofthe

biogaswasallanalyzedduringthereaction.Thesignificantchange

ofitscomposition(forCO2,CH4andN2)wasnotobserved,probably

due tohighcontentsofthesegases.ThereactivityofACforthe

adsorption of CO2 and CH4 should befurtherdone in orderto

evidencetheirimpactonthereactivityofACforH2Sfixation.

3.4.Sorptionreactivityofmixedsorbentsinbiogasmatrix

The results obtained above withthe single sorbents (AC or

calciumcarbonate-basedmaterial)showthateachsorbenthadits

own interaction with H2S. For AC, the physisorption was

predominant.Forcalciumcarbonate-basedmaterial,thecatalytic

oxidation,enhancedbyacid-basicreaction,mainlytookplace.Itis

usefultofocusontheinvestigationof thereactivityofdifferent

mixtureofACandCCW-DfortheremovalofH2Sfromthebiogas

matrix.Forthis,onlyonesorbentquantitywasused(2.5g).Five

sorbentmixturesweretestedwiththeweightratioofACtoCCW-D

equalto1:1;1:2;2:1,1:3;and3:1,bykeepingthetotalweightof 2.5g(Table5).Fig.7(a)showstheoutletconcentrationofH2Sasa

functionofthereactiontimeobtainedwiththesemixtures.The

resultsobtainedwiththeindividualCCW-DorACalsoincludedfor

comparison. Fig.7(b) represents the resultsof Fig. 7(a) bythe

accumulatedquantityofH2S.

InFig.7(a),itcanbeseenthattheincreaseoftheACcontentled

totheimprovementoftheperformanceofthemixture.Thusthe

order of the reactivity of these mixtures could be classed as

following: AC3:CCW-D1>AC2:CCW-D1>AC1:CCW-D1*

individ-ualAC>AC1:CCW-D2*AC1:CCW-D3>individualCCW-D.Infact,

after540minofreactiontime,thequantityofH2Saccumulatedin

eachsorbentwas:15mgforAC3:CCW-D1,14.5mgfor

AC2:CCW-D1,14mgforAC1:CCW-D1andACalone,10.5mgforAC1:CCW-D2,

10mgforAC1:CCW-D3and2mgforCCW-Dalone.At30minof

reaction,theoutletconcentrationofH2Swasalready5.6–7.3ppmv,

Fig.6.ExperimentalresultsinH2Spassingoverthesorbents(ACandCCW-D)fortheremovalofH2S(200ppmv)inbiogasmatrix(CH4=64%,CO2=31%,N2=5%),with experimentalconditionsofroomtemperatureandpressure,2500and500mgofsorbent,100mL/minofinputgas,100mLofwater:(a):OutletconcentrationofH2S;(b): AccumulatedquantityofH2Sfixedonsorbent.

Table5

CompositionofdifferentmixturesofACandCCW-Dusedinthiswork. Designation WeightratioofACtoCCW-S Totalweight,g

AC3:CCW-D1 3:1 2.5

AC2:CCW-D1 2:1 2.5

AC1:CCW-D1 1:1 2.5

AC1:CCW-D2 1:2 2.5

(10)

whichprogressivelyroseto123–130ppmat540min.An

impor-tant change in the performance was obtainedwhen using the

mixture containing 50wt% of AC (AC1:CCW-D1). This mixture

reachedthepractically-completeremovalofH2Sforatleastthe

first180min.Thenthismixtureslowlylostitsreactivitybutitwas

comparabletotheindividualACatthesametotalweightof2.5g.

TheincreaseoftheACcontentto66.7%(AC2:CCW-D1)and75%

(AC3:CCW-D1) allowed still increasing the performance of the

process.At75%ofAC,theoutletconcentrationofH2Swaskept

closetozeroformorethan480minandwasonlyof5.6ppmvafter

540min. This mixture was much more performant than the

individualACorCCW-D,whichsuggestsaveryinterestingsynergy

effectofthemixturefortheremovalofH2S.

3.5.Discussion

Two solid wastes (CCW-D and CCW-S) containing mainly

calciumcarbonatewereinvestigatedintheremovalofH2Sfrom

thegasphase.Undertheairmatrix,theywerereactivebecauseof

the availability of basic species (carbonate anions) for the

neutralization of sulfide species, and the catalytic activity of

variousmetalsinitiallypresentinthesewastes.Theyweremore

reactive than a pure commercial calcite. However, under the

reducingatmosphereofbiogas,withoutoxygen,thesesolidwastes

had only low reactivity, explained by the absenceof oxidation

reactions.

ThecommercialACusedasreferenceinthisworkwasfoundto

beefficientfortheremovalofH2Sfrombothairandbiogasmatrix.

However,whenACandCCW-Dwerecombined,theperformance

washighlyimprovedcomparedtotheindividualsorbentsinthe

biogasmatrix. Thesynergyeffectof this combinationmight be

explainedbythephysico-chemicalpropertiesofthetwosorbents.

CCW-D,containingmainlycalciumcarbonate,hashighbasicity.

ThisallowedacceleratingthedissolutionanddissociationofH2S

fromthegasphasetotheliquidphase.Butthiswasnotenoughto

maintaintheabatementofH2Swiththereactiontimeunderthe

biogasmatrixbecausedissolvedsulfidespecieswereaccumulated

inthereactor(withoutoxidationreactions).Thecombinationwith

AC allowed the fixation of dissolved sulfide species and thus

improvedthefixationrateofH2S.

In the aqueous solution, H2S can simply exist under the

dissolvedform(H2Saq)orcanbedissociatedtoHS"andS2",asa

functionofthepH.ThefavourableeffectofCCW-Donthereactivity of AC suggests that the dissociativeforms of sulfides HS",S2"

Fig.7. ExperimentalresultsinH2Spassingovermixturesofsorbents(AC:CCW-D)fortheremovalofH2S(200ppmv)inbiogasmatrix(CH4=64%,CO2=31%,N2=5%),with experimentalconditionsofroomtemperatureandpressure,2500mgofsorbents(weightratioofACtoCCW-Dof1:1,2:1,1:2,1:3and3:1),100mL/minofinputgas,100mLof water:(a):OutletconcentrationofH2S;(b):AccumulatedquantityofH2Sfixedonsorbent.

(11)

mightbepreferentiallyadsorbedonthesurfaceofAC.Inthiscase,

thebasicityofthesolidwasteisusefulfortheneutralizationof

protonscomingfromthedissociationofH2S.

InFig.7(a),themixtureAC3:CW-D1(composedof1.875gofAC

and0.625gofCCW-D)andthemixtureAC2:CW-D1(composedof

1.667gofACand0.833gofCCW-D)showhigherreactivitythan

theindividualAC, atthesame sorbentweightused(2.5g). The

mixtureAC:CW-D1(composedof1.25gofACand1.25gofCCW-D)

hadthecomparablereactivitythantheindividualAC.Takinginto

account the high cost of commercial AC compared to calcium

carbonate-basedwaste,itisveryinterestingtocombinethesetwo

materialsforthedesignofnewperformanceandlowcostsorbent.

Moreimportantly,consideringtheimportantannualproductionof

sodiumcarbonateandsodiumbicarbonate(about60milliontons

worldwide in2014[33]), largequantities ofcalcium

carbonate-basedwastesaregeneratedannually.Thehighavailability,thelow

costandthegoodreactivityforthefixationofacidgasofthese

wastes areimportantcriteriafor theviabilityof theprocess. In

addition,up-to-date,thesewastesarenotvalorizedforanyuseful

material. The biogas purification may open new route for the

valorizationofthesewastes,whichhavebeencreatingproblems

forammoniasodaplants[34–36].

Fig.8showstheevolutionoftheconcentrationofCH4,CO2,N2

andH2SwiththereactiontimeusingthemixtureAC3:CCW-D1in

thebiogasmatrix. BothCH4 and CO2 concentrationlevelswere

ratherstablethroughouttheexperiment,whichwasverypositive

forthestudy.Itmeansthatthesorbentsdevelopedinthisworkhas

highselectivityandcompatibilitytowardspolarcompounds,such

asH2SandthereforemoreappropriateforH2Sremoval.

Inthiswork,theonlypretreatmentappliedtothesolidwastes

wasthedryingat105!Ctoremovemoisture,becauseofthenature

ofthewastematerialstorage,whichismostlystoredoutsidewith

orwithoutcovers.Itispossibletoincreasetheperformanceofthe

sorbentbythermallytreating itathighertemperature.Thermal

treatment is known as an efficient treatment for desorbing

moleculesadsorbedonthesurfaceofagivensolidaswellasfor

combustionof eventualorganicmoleculespresentin theinitial

sorbents.Inthecaseofcalciumcarbonate-basedsorbent,athigh

temperature (above 610!C), thedecarbonation takes place and

increasesthebasicityandsothereactivityofthismaterial.Further

workwillfocusontheinfluenceofthethermaltreatmentonthe

reactivityofcalciumcarbonate-basedsorbents.

Actually,therearedifferentnovelaspectsofthepresentstudy.

First, H2Sremoval test was carried out with two differentgas

matrix,which representgaseous effluent(airmatrix)or biogas.

ThisallowsidentifyingtheimpactofCO2(andCH4)onthefixation

ofH2Sunderthesimilaroperational conditions.Theuseofthe

triphasicgas/liquid/solid processfor gascleaningseemed tobe

alsoanoveltyofthiswork.ThisacceleratesthetransferofH2Sfrom

gastoliquidphasewhichisfavourableforthecontactofsulfide

specieswiththesorbents.Finally,animportantaspectofthestudy

istheuseofmixturesofactivatedcarbonwithcalciumcarbonate

wasteasnewsorbentsforsorptiontest.Thesemixtureshadhigher

reactivity than AC or solid wastealone. It is believed that the

reductioninthequantityof AC,thatwillberequiredfor biogas

treatment as a result of substituting it with low cost waste

materialsassorbentswillleadtoreductionincostofAC,thereby

leading to overall reduction biogas purification and upgrading

costs.

Theresultsofthecurrentstudyagreedwithearlierworksofour

teamandotherresearchersonH2Sremovalfromgasphase.Galera

Martinez [32] worked on valorization of industrial carbonate

residuesforthetreatmentofhydrogensulfideingaseffluents,and

explained the catalytic oxidation of H2S, catalyzed by various

metalspresentinthesesolidwastes(Ca,Mg,Feetc.).Also,Stita

etal.[37]studiedmetal-dopedapatiticcalciumphosphatesforthe

removalofhydrogen sulfide fromgasphase, while Pham Xuan

etal.[28]studiedonthevalorizationofcalciumcarbonate-based

solidwastesforthetreatmentofhydrogensulfidefromgasphase.

Lastly,PhamMinhetal.[38]conductedthesimilarresearchbased

on calcium phosphate-based materials starting from calcium

carbonateand orthophosphoric acidfor theremovalof lead(II)

from an aqueous solution. In addition to these, Lasocki [39]

investigatedbiogastreatmentbyremovalofhydrogensulfideand

carbondioxideatlaboratory-scale,usingbothabsorptionsinliquid

phase (barbotage process) and solid bed of reagent. Also, H2S

removalfrombiogasonsludge-derived adsorbentswas

investi-gatedbyotherresearchers[24,40–42],usingsimilartechniques.

Theseearlierinvestigationsandotherstudiesintheliteraturewere basedsolelyonsyntheticwastegasmatrix(H2Sinair)only,except

Fig.8.EvolutionoftheconcentrationofCH4,CO2,N2andH2SattheoutletofthereactorasafunctionofthereactiontimewhenusingthemixtureAC3:CCW-D1inthebiogas matrix.

(12)

Ortiz[24],whousedsimulatedbiogas.Thismightbeduetothefact

thatCO2mightcompeteagainstH2Sinadsorptiondependingon

theporousstructureoftheadsorbentandthealkaliconstituents

sincetheyarebothacidgases.Whereasthisstudywasbasedon

bothsimulatedbiogasmatrix(H2Sinbiogas)andsyntheticwaste

gasmatrix(H2Sinair),usingtriphasicgas/liquid/solidprocessat

roomtemperatureandatmosphericpressure.Asstatedearlierand

showninFig.8,bothCH4andCO2concentrationlevelswererather

stablethroughouttheexperiment,whichwasverypositiveforthe

study.

4. Conclusions

Inthis study, AC wasfoundtobethe mostreactivefor H2S

removalfromthegasphase,followedbyCCW-D,CCW-Sandpure

commercialcalcite.Physisorptionwas predominantwhenusing

AC while acid-basic reaction and catalytic oxidation were

predominant with calcium carbonate-based sorbents.

Conse-quently, AC slowly lost its performance while the calcium

carbonate-basedwastes keptconstantlytheirreactivity(bythe

catalyticoxidation).Inthebiogasmatrix,onlyACandCCW-Dwere

investigated. CCW-D quickly lost its reactivity because no

oxidationreactiontookplace, whichwasdue totheabsenceof

oxygen in the biogas matrix used. AC showed again its high

performanceforthephysisorptionofH2S.Butitsreactivitywas

lowerin thebiogasmatrixthan in theairmatrix (atthesame

sorbentweightusedof0.5g), whichcouldbeexplainedbythe

competitive adsorption of CH4 and CO2 present in the biogas

matrix.

ThereactivityofdifferentmixturesofACandCCW-Dwerealso

investigatedinthebiogasmatrix.Atthesamesorbentloadof2.5g

withat least50wt%of AC,a synergyeffectofthemixturewas

observed for the removal of H2S, compared to the individual

sorbent.Thisbeneficialeffectwasexplainedbythecombinationof

the high basicity of CCW-D (by the dissolution of calcium

carbonate)andthehighspecificsurfaceareaofAC,availablefor

thefixationofthesulfide species.Therefore,calciumcarbonate

wastecanbeusedasco-sorbentwithACinthetriphasicprocessfor

theremovalofH2Sfromthegasphase.Thisopensnewperspective

forthevalorizationofthiskindofsolidwastes,inparticularlyfor

thepurificationofbiogas.

Acknowledgements

ThefirstauthoracknowledgesthesupportfromtheSchoolof

Civil Engineering,UniversityCollegeDublin, tuition scholarship

support from Student Universal Support Ireland (SUSI) and

Universite’ de Toulouse, Mines Albi, CNRS UMR 5302, Centre

RAPSODEE,CampusJarlard, Albi,F-81013cedex 09,France.The

authorgratefullyacknowledgescolleaguesand technicalstaffat

RAPSODECenterfortechnicalhelp.

References

[1]H.Böni,R. Hischier,M.Lehmann,R.Zah,M.,Gauch,P.Wager, Lifecycle assessmentofenergyproducts:environmentalimpactassessmentofbiofuels –executivesummary(onlytranslatedportion),(2007).

[2]F.VanForeest,PerspectivesforBiogasinEurope,OxfordInstituteforEnergy Studies,2012.http://www.oxfordenergy.org/wpcms/wp-content/uploads/ 2012/12/NG-70.pdf.

[3]G.Busch,J.Großmann,M.Sieber,M.Burkhardt,Anewandsoundtechnology forbiogasfromsolidwasteandbiomass,WaterAirSoilPollut.Focus9(2009) 89–97,doi:http://dx.doi.org/10.1007/s11267-008-9195-5.

[4]C.L.Hansen,D.Y.Cheong,Chapter23–Agriculturalwastemanagementinfood processing,Handb.Farm,DairyFoodMachEng,(2013),pp.619–666,doi: http://dx.doi.org/10.1016/B978-0-12-385881-8.00023-9.

[5]SwedishGasTechnologyCentre,Basicdataofbiogas,Phys.Radiol.(2012)719– 739ISBN978-91-85207-7.

[6]S.E.Hosseini,M.A.Wahid,Developmentofbiogascombustionincombined heatandpowergeneration,Renew.Sustain.EnergyRev.40(2014)868–875, doi:http://dx.doi.org/10.1016/j.rser.2014.07.204.

[7]C.F. Cullis,M.M. Hirschler,Atmospheric sulphur:natural andman-made sources,Atmos.Environ.14(1980)1263–1278,doi:http://dx.doi.org/10.1016/ 0004-6981(80)90228-0.

[8]O. Badr, S.D. Probert, Atmospheric sulphur: trends, sources, sinks and environmentalimpacts,Appl.Energy47(1994)1–67,doi:http://dx.doi.org/ 10.1016/0306-2619(94)90030-2.

[9]J.Wang,Y.Zhang,L.Han,L.Chang,W.Bao,Simultaneousremovalofhydrogen sulfideandmercuryfromsimulatedsyngasbyiron-basedsorbents,Fuel103 (2013)73–79,doi:http://dx.doi.org/10.1016/j.fuel.2011.10.056.

[10]W.M. Budzianowski, A review of potential innovations for production, conditioningandutilizationofbiogaswithmultiple-criteriaassessment, Renew.Sustain.EnergyRev.54(2016)1148–1171,doi:http://dx.doi.org/ 10.1016/j.rser.2015.10.054.

[11]J.I.Huertas,N.Giraldo,S.Izquierdo,RemovalofH2SandCO2frombiogasby

amineabsorption,MassTransf.Chem.Eng.Process.307(2011),doi:http://dx. doi.org/10.5772/20039.

[12]E.Ryckebosch,M.Drouillon,H.Vervaeren,Techniquesfortransformationof biogastobiomethane,BiomassBioenergy35(2011)1633–1645,doi:http://dx. doi.org/10.1016/j.biombioe.2011.02.033.

[13]F.Pouliquen,C.Blanc,E.Arretz,I.Labat,J.Tournier-Lasserve,A.Ladousse,J. Nougayrede,G.Savin,R.Ivaldi,M.Nicolas,J.Fialaire,R.Millischer,C.Azema,L. Espagno,H.Hemmer,J.Perrot,Hydrogensulfide,Ullmann’sEncycl.Ind.Chem., Wiley-VCHVerlagGmbH&Co.KGaA,2000,doi:http://dx.doi.org/10.1002/ 14356007.a13_467.

[14]N.Abatzoglou,S.Boivin,Areviewofbiogaspurificationprocesses,Biofuels Bioprod.Biorefin.3(2009)42–71,doi:http://dx.doi.org/10.1002/bbb.117. [15]X.Zhang,G.Dou,Z.Wang,L.Li,Y.Wang,H.Wang,Z.Hao,Selectivecatalytic

oxidationofH2Soverironoxidesupportedonalumina-intercalatedLaponite claycatalysts,J.Hazard.Mater.260(2013)104–111,doi:http://dx.doi.org/ 10.1016/j.jhazmat.2013.05.008.

[16]I.Omri,H.Bouallagui,F.Aouidi,J.J.Godon,M.Hamdi,H2Sgasbiological

removalefficiencyandbacterialcommunitydiversityinbiofiltertreating wastewaterodor,Bioresour.Technol.102(2011)10202–10209,doi:http://dx. doi.org/10.1016/j.biortech.2011.05.094.

[17]R.Lebrero,A.C.Gondim,R.Perez,P.A.Garcia-Encina,R.Munoz,Comparative assessmentofabiofilter,abiotricklingfilterandahollowfibermembrane bioreactorforodortreatmentinwastewatertreatmentplants,WaterRes.49 (2014)339–350,doi:http://dx.doi.org/10.1016/j.watres.2013.09.055. [18]S.Kang,Y.Seo,W.Jang,Y.Seo,C.Fossil,GasHydrateProcessforRecoveryofCO,

(2009).http://citeseerx.ist.psu.edu/viewdoc/download? doi=10.1.1.628.8870&rep=rep1&type=pdf.

[19]X.Wang,G.Chen,L.Yang,L.Zhang,Studyontherecoveryofhydrogenfrom refinery(hydrogen+methane)gasmixturesusinghydratetechnology,Sci. ChinaSer.BChem.51(2008)171–178, doi:http://dx.doi.org/10.1007/s11426-007-0131-8.

[20]Q.Sun,H.Li,J.Yan,L.Liu,Z.Yu,X.Yu,Selectionofappropriatebiogasupgrading technology-areviewofbiogascleaning,upgradingandutilisation,Renew. Sustain.EnergyRev.51(2015)521–532,doi:http://dx.doi.org/10.1016/j. rser.2015.06.029.

[21]H. Tajima, A. Yamasaki, F. Kiyono, Energy consumption estimation for greenhousegasseparationprocessesbyclathratehydrateformation, Energy29(2004)1713–1729,doi:http://dx.doi.org/10.1016/j. energy.2004.03.003.

[22]B.Castellani,F.Rossi,M.Filipponi,A.Nicolini,Hydrate-basedremoval of carbondioxideandhydrogensulphidefrombiogasmixtures:experimental investigationandenergyevaluations,BiomassBioenergy70(2014)330–338, doi:http://dx.doi.org/10.1016/j.biombioe.2014.08.026.

[23]R.Muñoz,L.Meier,I.Diaz,D. Jeison,Areviewonthestate-of-the-artof physical/chemicalandbiologicaltechnologiesforbiogasupgrading,Rev. Environ.Sci.Biotechnol.14(2015)727–759,doi:http://dx.doi.org/10.1007/ s11157-015-9379-1.

[24]F.J.GutiérrezOrtiz,P.G.Aguilera,P.Ollero,Biogasdesulfurizationbyadsorption onthermallytreatedsewage-sludge,Sep.Purif.Technol.123(2014)200–213, doi:http://dx.doi.org/10.1016/j.seppur.2013.12.025.

[25]M.Mora,M.Fernández,J.M.Gómez,D.Cantero,J.Lafuente,X.Gamisans,D. Gabriel,Kineticandstoichiometriccharacterizationofanoxicsulfideoxidation bySO-NRmixedculturesfromanoxicbiotricklingfilters,Appl.Microbiol. Biotechnol.99(2014)77–87, doi:http://dx.doi.org/10.1007/s00253-014-5688-5.

[26]A.M. Montebello, Aerobic Biotrickling Filtration or Andrea Monzón Montebello,UniversitatAutonomadeBarcelona,Bellatera,2013.

[27]J.-H.Yoon,H.Lee,Clathratephaseequilibriaforthewater-phenol-carbon dioxidesystem,AIChEJ.43(1997)1884–1893,doi:http://dx.doi.org/10.1002/ aic.690430723.

[28]H.PhamXuan,D.PhamMinh,M.GaleraMartı’nezz,A.Nzihou,P.Sharrock, Valorizationofcalciumcarbonate-basedsolidwastesforthetreatmentof hydrogensulfidefromthegasphase,Ind.Eng.Chem.Res.54(2015)4915– 4922,doi:http://dx.doi.org/10.1021/acs.iecr.5b00764.

[29]N.Yoshizawa,K.Maruyama,Y.Yamada,M.Zielinska-Blajet,XRD.evaluationof CO2activationprocessofcoal-andcoconutshell-basedcarbons,Fuel79

(2000)1461–1466,doi:http://dx.doi.org/10.1016/S0016-2361(00)00011-9. [30]A.Guinier,X-RayDiffractionInCrystals,ImperfectCrystals,andAmorphous

(13)

[31]C.Winter,J.N.Caetano,A.B.C.Araújo,A.R.Chaves,I.C.Ostroski,B.G.Vaz,C.N. Pérez,C.G.Alonso,Activatedcarbonsforchalconeproduction: Claisen-Schmidtcondensationreaction,Chem.Eng.J.303(2016)604–610,doi:http:// dx.doi.org/10.1016/j.cej.2016.06.058.

[32]M.GaleraMartinez,Valorisationdesrésiduscarbonatésindustrielspourle traitementdesulfured’hydrogènedansleseffluentsgazeux,Universitéde Toulouse,2015.

[33]SodiumCarbonateProductions,(n.d.).http://www.societechimiquedefrance. fr/extras/Donnees/mine/naco/texnaco.htm(Accessed1August2016). [34]G.Steinhauser,CleanerproductionintheSolvayProcess:generalstrategies

andrecentdevelopments,J.Clean.Prod.16(2008)833–841,doi:http://dx.doi. org/10.1016/j.jclepro.2007.04.005.

[35]T. Kasikowski, R. Buczkowski, B. Dejewska, K. Peszy!nska-Białczyk, E. Lemanowska,B.Igli!nski,Utilizationofdistillerwastefromammonia-soda processing,J.Clean.Prod.12(2004)759–769,doi:http://dx.doi.org/10.1016/ S0959-6526(03)00120-3.

[36]C.Gao,Y.Dong,H.Zhang,J.Zhang,Utilizationofdistillerwasteandresidual motherliquortoprepareprecipitatedcalciumcarbonate,J.Clean.Prod.15 (2007)1419–1425,doi:http://dx.doi.org/10.1016/j.jclepro.2006.06.024. [37]S.Stita,M.GaleraMartínez,H.PhamXuan,D.PhamMinh,A.Nzihou,P.

Sharrock,Metal-dopedapatiticcalciumphosphates:preparation, characterization,andreactivityintheremovalofhydrogensulfidefromgas phase,Compos.Interfaces22(2015)503–515,doi:http://dx.doi.org/10.1080/ 09276440.2015.1049096.

[38]D.PhamMinh,N.D.Tran,A.Nzihou,P.Sharrock,Calciumphosphatebased materialsstartingfromcalciumcarbonateandorthophosphoricacidforthe removaloflead(II)fromanaqueoussolution,Chem.Eng.J.243(2014)280– 288,doi:http://dx.doi.org/10.1016/j.cej.2014.01.032.

[39]J.Lasocki,K.Kołodziejczyk,A.Matuszewska,Laboratory-scaleinvestigationof biogastreatmentbyremovalofhydrogensulfideandCarbonDioxide,Pol.J. Environ.Stud.24(2015)1427–1434,doi:http://dx.doi.org/10.15244/pjoes/ 35283.

[40]A.Ansari,A.Bagreev,T.J.Bandosz,EffectofadsorbentcompositiononH2S removalonsewagesludge-basedmaterialsenrichedwithcarbonaceous phase,CarbonN.Y.43(2005)1039–1048,doi:http://dx.doi.org/10.1016/j. carbon.2004.11.042.

[41]W.Yuan,T.J.Bandosz,Removalofhydrogensulfidefrombiogason sludge-derivedadsorbents,Fuel86(2007)2736–2746,doi:http://dx.doi.org/10.1016/j. fuel.2007.03.012.

[42]Y.Xiao,S.Wang,D.Wu, Q.Yuan, Experimentalandsimulationstudyof hydrogensulfideadsorptiononimpregnatedactivatedcarbonunder anaerobicconditions,J.Hazard.Mater.153(2008)1193–1200,doi:http://dx. doi.org/10.1016/j.jhazmat.2007.09.081.

[43]M.Persson,O.Jonsson,A.Wellinger,Biogasupgradingtovehiclefuelstandards andgridinjection,IEABioenergy(2007)1–32.

[44]L.BailónAllegue,J.Hinge,Biogasandbio-syngasupgrading,DTURep.(2012) 1–97.

[45]L.BailónAllegue,J.Hinge,BiogasUpgradingEvaluationofMethodsforH,( 2014),pp.1–31.

[46]F.Bauer,C.Hulteberg,T.Persson,D.Tamm,BiogasUpgrading–Reviewof CommercialTechnologies,SwedishGasTechnol.Centre,SGC,2013,pp.82SGC Rapport2013:270.

[47] A.Petersson,A.Wellinger,Biogasupgradingtechnologies–developmentsand innovations,IEABioenergy(2009)20.http://typo3.dena.de/fileadmin/biogas/ Downloads/Studien/IEA-BiogasUpgradingTechnologies2009.pdf.

Figure

Fig 1. Flow diagram of laboratory-scale setup for H 2 S removal from gas phase.
Fig. 2 shows XRD patterns of the initial sorbents. For the commercial AC, two weak and broad peaks around 25 and 45 ! were observed which are characterized for amorphous
Fig. 4 shows the particle size distribution of all the raw materials before pretreatment
Fig. 5. Experimental results in H 2 S passing over the sorbents (AC, CALCITE, CCW-D and CCW-S) for the removal of H 2 S (200 ppmv) diluted in air with experimental conditions of room temperature and pressure, 500 mg of sorbent, 100 mL/min of input gas, 100
+3

Références

Documents relatifs

Il a été montré par le groupe du professeur Férézou que la métathèse macrocyclique peut être aussi utilisée pour la formation de diènes macrocycliques, comme pour

Dans ce chapitre, le modèle biomécanique développé pour l’étude des veines profondes a été utilisé pour simuler plusieurs scénarios d’applications, ce qui nous a permis

Consequently, our proposed irrigation scheduler and flexi- bility allocation mechanisms increase the potential of the grid to host renewable energy sources while reducing

Entre les profils 80 et 85, là où l’abaissement du cordon a été le plus spectaculaire lors de la tempête Johanna puisqu’il avait perdu 2 m de hauteur, le sommet s’est exhaussé

the number of images per model has to be carefully considered, since a large number of silhouettes provide more complete descriptions but also increases the

illustrates the stress softening, defined by the difference between computed (monotonic) and experimental (cyclic) maximum ax- ial/shear engineering stress components at the 128th

Eight primary themes related to the pandemic emerged in the sampled messages: (1) a lack of understanding of SARS-CoV-2 and the COVID-19 disease; (2) health behavior and acceptance

Ce qui pourrait vraisemblablement expliquer en partie le taux de mortalité plus élevé, après les coups de chaleur de 7 heures, chez les poulets n’ayant pas été